A report released on Saturday said the cruise control and braking functions of a Mercedes-Benz C200L were normal, after the driver claimed the car was locked at high speed on March 14.
The car was going nearly 120 kilometers per hour on a highway in Henan province, and the driver said he couldn't stop it for about 100 km.
The report, prepared by the China Vehicle Forensic Center (Beijing), said the vehicle's braking system and cruise control systems were working normally, and it found no evidence of any abnormality, according to China Central Television.
The driver, Xue Lishan, said he planned to drive the new luxury vehicle from Jiaozuo, Henan province, to Chengdu, Sichuan province, for business. He told CCTV that he activated the car's cruise control at a speed of 120 km/h - the posted speed limit - on the highway connecting Henan and Shaanxi provinces.
Cruise control allows a driver to set any desired speed and then take his or her foot off the pedal, which is more comfortable and fuel-efficient during long, uninterrupted stretches of driving.
Later, Xue said, he found he was unable to turn off the cruise control and couldn't slow the car down. He tried every measure he could think of, he said, including normal braking, pulling the handbrake and seeking emergency help from Mercedes-Benz customer service via the vehicle's emergency communication system.
Mercedes told him to insert his electronic key, he said, but he was unable to reach it, as it was in the back seat. Some high-tech key systems allow a vehicle to be operated if the key is simply nearby. Mercedes also told him to try shifting the gears into neutral, but he said that measure also failed.
When approaching the toll station at the Henan-Shaanxi provincial boundary, Xue sought urgent help from traffic police in Sanmenxia on his cellphone, and they immediately cleared three lanes at the toll station. According to surveillance video, the car passed the station safely at high speed.
Finally, Xue said, he was able to stop the car after finding that opening the vehicle's door slowed it down. The next day, he continued to drive the car and arrived in Chengdu.
A week after the incident, Xue and Mercedes-Benz agreed to seal the vehicle and in late April turned it over to a third party - China Vehicle Forensic Center (Beijing) - for an inspection.
The report said, among other things, that the vehicle cannot be slowed down or stopped by opening its door at speeds over 2 km/h, whether or not the driver is wearing a safety belt.
Xue said on his Sina Weibo on Sunday that he respected the results but was still confused as he told CCTV that he did in fact experience a malfunction. Meanwhile, Mercedes-Benz told CCTV that it fully respected and agreed with the report.
Apart from finding that the car was running normally when it was checked, the appraisal also detected a turnoff record for the cruise control, which - based on the distance the car had traveled - happened after the incident on March 14.
Xue expressed his confusion on Sina Weibo, saying he didn't use the cruise control after the incident.
According to Beijing News, traffic police in Sanmenxia said on Sunday they had not neither called for nor reviewed the appraisal, and any facts would be open to the public after further investigation.
